1. Field of the Invention
The present invention relates to an information processing device containing a printed wiring board on which electronic components are mounted, a communication apparatus comprising such information processing devices installed in a rack, and a method of connecting external cables to the information processing device.
2. Description of the Related Art
Conventional communication apparatus comprises a vertical row of information processing devices each containing a printed wiring board on which electronic components are mounted, and is installed at the site of a base station or the like. Such electronic components include heat-emitting devices, and accordingly, the information processing device is often equipped with a plurality of fans or the like constituting a ventilation arrangement for cooling the internal components (see, e.g., Unexamined Japanese Patent Publication No. H01-238097).
FIGS. 21A to 21C schematically illustrate an exemplary construction of a conventional communication apparatus, wherein FIG. 21A is a front view of the apparatus, FIG. 21B is a rear view of the apparatus, and FIG. 21C is a left side view of the apparatus.
The communication apparatus 101 comprises a vertical row of information processing devices 103 arranged on a rack 102 constituted by metal plates welded together. In the figures, only one information processing device 103 is shown for convenience' sake. The information processing device 103 contains a printed wiring board on which electronic components are mounted. Also, external cables 104 for inputting/outputting signals and power cables 105 for supplying electric power are connected to the front and rear, respectively, of the information processing device 103.
FIGS. 22A and 22B schematically illustrate an exemplary construction of the conventional information processing device, wherein FIG. 22A is a front view of the device and FIG. 22B is a rear view of the device.
The front of the information processing device 103 is provided with connectors 106 to which personal computers etc. are connected, a slot 107 in which a memory card storing predetermined settings is inserted, a display section 108 constituted by a plurality of LEDs, and connection ports 109 to which external cables 104 are connected. A plurality of vent holes 110 for admitting fresh air are formed in the other region of the front surface.
The rear of the information processing device 103 is provided with power supply terminals 111 to which power cables 105 are connected, motor-driven fans 112, and breakers 113 for cutting off the power supply.
Meanwhile, with the recent tendency toward larger capacity and higher output of communication apparatus, an increasing number of external cables are connected to individual information processing devices. To secure a connection space for numerous external cables, the areas of the front and rear surfaces of the information processing device are increased, for example.
However, the following problems arise when a large number of external cables are connected.
Specifically, in communication apparatus in which numerous external cables are connected to the front and rear of each information processing device, the front and rear surfaces of each device need to be increased to secure a connection space for the external cables. As a result, the body of each information processing device increases in size, requiring an installation space larger than the capacity that the internal electronic circuitry originally requires. Namely, increase in the number of external cables leads to useless increase of the space occupied by the information processing device.
Also, in small-sized communication apparatus with a relatively small height, printed wiring boards are horizontally positioned within each information processing device and cooling air is introduced into the device so as to flow in the depth direction. Consequently, the front and rear of the device need to be provided with a cooling arrangement such as vent holes and fans, besides the connection ports for the external cables. In this case, the number of external cables and the size of the cooling arrangement are the factors that determine the overall size of the information processing device and thus of the communication apparatus. To reduce the size of the information processing device without decreasing the number of external cables, expensive components such as small-sized, high-output motors need to be used, giving rise to a problem that the cost increases.
In medium- or large-sized communication apparatus with a relatively large height, printed wiring boards are vertically positioned within each information processing device and cooling air is introduced into the communication apparatus so as to flow in the vertical direction. Consequently, the body of the information processing device is increased in height and occupies an installation space larger than the capacity that the internal electronic circuitry originally requires. It is also necessary to provide the top and bottom of the communication apparatus with a cooling arrangement such as fans and convection inducers, which entails useless increase of the installation space for the communication apparatus.